1. Field of the Invention
The present invention is related to an electrical connector, especially to a straddle mount connector which is straddle-mounted on an edge of a printed circuit board with independent support subassemblies carrying signal and grounding conductors thereon.
2. Description of the Related Art
A right-angled connector is straddle mounted on the edge of a printed circuit board to save space on the printed circuit board and facilitate the installation of some larger peripheral devices. The contacts of a right angle connector can be soldered after their right-angled tails extend through penetrated holes disposed in the printed circuit board or as a surface mount, directly on the surfaces of the printed circuit board. The through-hole type soldering will occupy space on both sides of the printed circuit board, results in limited soldering space for more and more circuits or electronic parts. The corresponding mounting and soldering process for the through-hole type soldering is complicated and time consuming because right-angle shaped tails of these contacts need to be positioned by a spacer before they are inserted into the holes of the printed circuit board and held in position by board locks before soldering proceeds. Surface-mount type soldering has a simpler and faster process, though board locks are still needed. Tails of surface mount contacts extending straightly out of the housing of the connector can be soldered on either one or two sides of the printed circuit board. Long U.S. Pat. No. 5,893,764 and Chen et al. U.S. Pat. No. 5,292,265 both introduce connectors having two rows of contacts where contacts of one row are engaged on one side of the printed circuit board while contacts of the other row are engaged on the opposite side. However, more rows of contacts are usually adopted in current connector designs for high density and high frequency applications, and sometimes a grounding means is needed to suppress generated noise between these parallel-arranged contacts. Cohen et al. U.S. Pat. No. 6,152,742 and Grabbe et al. U.S. Pat. Nos. 5,320,541 and 5,813,871 all introduce a straddle mount connector having a grounding plate disposed between two rows of contacts. Usually, the grounding means has tails extending to be soldered onto the same edge of the printed circuit board to establish electrical grounding paths. An arrangement of signal contacts and the ground means that provides good electrical performance inside the connector housing should also be helpful for both assembling and mounting processes. In the Grabbe design mentioned above, tails of the grounding plate are inserted into holes disposed on the edge side of the printed circuit board. Obviously, additional and specialized parts are needed in this application, which may cause some difficulty in the manufacturing processes and unnecessary cost.
Furthermore, spreading soldering pads on the same surface of the printed circuit board into two rows is desired to simplify the soldering process of the straddle mount connector as mentioned above because the distance between two neighboring pads can be enlarged to avoid solder wicking. Mohtar et al. U.S. Pat. No. 6,312,265 and Humphrey U.S. Pat. No. 5,895,278 show two kinds of staggered tail arrangement for solder tails on either one or two sides of a printed circuit board. However, space on the printed circuit board is unnecessarily occupied and fewer contacts can be soldered on limited pads disposed thereon in Mohtar""s design. Conversely, the Humphrey""s design utilizes complicated contact tails which are hard to manufacture and be positioned on the right pads of the printed circuit board. It will make both of these two designs much more complicated if any grounding means is taken into consideration in the high-speed transmission.
Therefore, an object of the present invention is to provide a straddle mount connector having simple and facilely assembled parts to form a symmetrical electrical conductor arrangement in the connector for faster production and cost saving.
Another object of the present invention is to provide a straddle mount connector having connected ground reference between different rows of high-speed transmission signal contacts in order to get better electrical performance and be in need of fewer tails mounted onto the printed circuit board where the connector is straddle mounted.
Another object of the present invention is to provide a straddle mount connector having a staggered arrangement for solder tails of signal parts and ground parts that no complex structure of contact tails or processing of the engaged printed circuit board is needed, and the final solder joints of connector tails and pads on the board are stronger because the solder paste on any pad is not damaged by other connector tails unnecessarily passing through the pad before soldering.
Another object of the present invention is to provide a straddle mount connector having conductor modules firmly installed therein which keep the signal and ground conductors mounted thereon in position while the connector is straddle mounted on a printed circuit board or mated with a complementary connector.
To obtain the above objects, an electrical connector straddle-mounted on an edge of a printed circuit board includes an insulative housing having an elongated groove for mating. A plurality of receiving channels, each of which is used to receive a support subassembly, are formed adjacently to and communicated with the mating groove. The support subassembly includes a plane-like base having a plurality of parallel arranged passageways formed on one surface of the base and a protrusion formed on the other. Pin-like signal contacts are inserted into the passageways respectively along the surface of the base and a plate-like ground member is installed abutting against the other surface of the support subassembly to be fixed on the protrusion. Every contact includes an engaging end exposed to the mating groove once the contact is inserted into the housing accompanying the support subassembly, and a tail end extending out of the receiving channel in a suspended status. And the ground member includes a plurality of contacting legs extending away from the ground member for a predetermined distance and being suspended similar to the tail end of every contact.
Specifically, the support subassemblies are installed into the connector housing in a symmetrical arrangement with every two support subassemblies received in two adjacent receiving channels of different rows being arranged reversely to have tail ends of their contacts and contacting legs of their ground member facing toward each other respectively to form a space between them for holding the edge of the printed circuit board therein. Thus, no matter how many contacts are in a row in the connector, the support subassemblies used in the connector are same that can be made easily and have lower cost. And every row of contacts can have their own accessible ground reference in the same support subassembly for effectively reducing crosstalk between these contacts. A bar portion transversely is formed protruding from one surface of the base having passageways. Several holding elements are formed in a hook shape on one edge side of the ground member. Tabs are sheared out of predetermined locations of the middle portion of the ground member and extend laterally in a predetermined length along a direction reverse to the pointing direction of the hook end of the holding element. Thus, the bar portion, holding elements and a protrusion formed on the other surface of the base are all used to stop the insertion of the support subassembly when it is assembled into the housing. And the tabs can be locked in the connector housing to prevent from the reverse movement of the support subassembly. Therefore, all of the support subassemblies with conductors, the contacts and ground member installed thereon, are firmly disposed in the connector housing for perfect engagement of these conductors while the connector is installed on a printed circuit board or mated with a complementary connector.
In addition, every holding element of the ground member will be formed toward the center of the housing and hook into a corresponding aperture formed on the housing. And the corresponding holding elements of two neighboring ground members, installed on two adjacent support subassemblies, are inserted in common apertures respectively, to become electrically connected so that these two electrically connected grounds member can establish a common ground path to the printed circuit board and let their neighboring signal contacts achieve better electrical performance when they are coupled with the connected ground members. Thus, the number of ground tails needed to engage with the printed circuit board where the connector is straddle mounted become less and the edge of the printed circuit board does not require machining for specific connection, but disposed with simple solder pads on both of its sides.
Furthermore, contacting legs of the ground member and tail ends of contacts all extend outside of the connector housing and their free ends used for electrical engagement with the printed circuit board are arranged in two different rows parallel to the lengthwise direction of the connector respectively because of their different lengths and inclined shapes. And the contacting legs of the ground member and tail ends of contacts are staggered with each other along the length of the connector. Thus, the tail ends of contacts do not pass over the ground pads of the printed circuit board used to engage with the ground member and damage preset solder paste thereon when the connector is installed onto the printed circuit board, so that the final solder joints of the connector tails and ground pads are more uniform.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.